Speedometer construction



Oct. 9, 1928. v 1,687,251

A. H. JOSEPH SPEEDOMETER CONSTRUCTION Filed oct. s, 1925 Patented Oct. 9, 1928.

UNITED STATES PATENT OFFICE.

ARTHUR H. JOSEPH, OF DETROIT, MICHIGAN, ASSIGNOR T0 THE MILEOMETER COM- IPANY, OF CHICAGO, ILLINOIS,

SPEEDOMETER A CORPORATION OF ILLINOIS.

CONSTRUCTION.

Application filed October 3, 1923. Serial No. 666,356.

.The invention has among its other objects` the vproduction of a device of the kind described'in which a plurality of springs may be used so as t0 overcome the variance in the strengths of spring material and in which the total strength of the combined springs is always constant.

Another object of my invention is to provide an adjustment for increasing or decreasing the pressure of the springs mentioned.

Many other objects and advantages of the construction herein shown and described will 'be obvious to those skilled in the art from the disclosures herein given.

To this end my invention consists in the novel construction, arrangement and combination of parts herein shown and described, and more particularly pointed out in' the claims.

AIn the drawings, wherein like reference characters 'indicate like or corresponding parts:

Fig. 1 is a sectional view taken through my device;

Fig. 2 is a section taken substantially on line 2-2 of Fig. 1; A

Fig. 3 is a fragmentary detail of the plural spring construction;

Fig. 4 is a section taken on line 4 4 of Fig. 1; and

Fig. 5 is a section taken on line 5-5 0f Fig. 1.

Referring to the drawings in which I have illustrated the preferred embodiment of myA a casing of suitablev as to be rotatably driven therewith, the outer edges of the impellers or vanes being spaced adjacent the inner periphery'of a cup or flanged member nxedly arranged in the casing and having air intake openings 5 through the web thereof.

An indicator wheel 6 having vanes 7 arranged about its periphery is rotatably mounted adjacent the impeller or fan 4, but independently thereof, as shown, said indicator wheel having a journal 9, whose ends bear in sockets 1() carried by a frame-'work or bracket 8. The indicator wheel has a cam part 13 extending inwardly of the outer periphery thereof to adjacent the rotational axis of the indicator.

It will be apparent that inasmuch as the indicator is freely rotatable, the air directed by the fan 4 will cause av rotation of the indicator wheel. In order to limit the rotational movement of the indicator, an elongated opening k11 is provided therethrough and through which a stationary bar 12 projects, to engage the ends of the openings 10, as shown more particularly in Fig. 2. j n In order vthat the movement of the indicator will not be vibratory, but will be steady and accurate at all times and in order to retrieve the indicator to a Zero position whenever the vehicle is at rest, I have arranged a leaf spring 16, connected at one end to the bracket 8, the other end of said spring-having an anti-friction member 19 thereat, preferably a glass bead, to engage with the cam surface of the cam 13. The leaf spring 17 is rigidly secured between the bracket and an adjusting plate 30 by a pin 34, a screw 18 threaded in plate 30, passing through the spring, and bearing on the bracket 8, being wprovided for varying the tension of the spring (see Fig. 5). Similarly, as shown in Fig. 4, the spring 16 is secured between the bracket 8 and an adjusting plate 31 by a pin 33 and its tension adjusted by means of a screw v18.

Adjacent the inner end 14 of the cam 13, the cam is provided with a throat 15 so that at the lower speeds the spring 16 will exert a direct sidethrust against the cam rather 'han a sliding movement. In general practice the vehicle speeds up to approximately five miles are not important, but speeds above this amount and which'are generally encountered, need be accurately known.

In order to equalizeV the pressure on the glass bead so as to prevent breakage or other injury thereto, a second leaf spring 17 is used, the free end of said latter spring being engageable with said bead after the bead has been pushed outwardly by the movement of the cam. The other end of said spring is secured to the frame-work adjacent the end of the spring 16.

By using two springs any variance in the spring material may be overcome so that none of said spring material need be wasted. These springs are sorted out into plus and minus, referring to their strengths, and are then combined in such a Way so as to give a known and predetermined strength. If, for example, we desire a spring that has a strength of 10, we may use a pair of springs, one having a strength of four and ninetenths and the other a strength of live and one-tenth so that the two springs together equal the desired combined strength. Thus the springs singly may be of slightly different strengths and the variance between the springs may be overcome by the use of a pair of heavier and lighter springs, which together combine to make up a total given resistance or strength. In this manner none of the spring material need be wasted and the pressure of the combined springs upon the cam will be constant in every case.

Having thus described my invention, it is obvious that various immaterial modiiications may be made in the same without departing from the spirit of my invention; hence I do not wish to be understood as limiting myself to the exact form, construction. arrangement and combination of parts herein shown and described or uses mentioned.

What I claim as new and by Letters Patent is:

l. In combination, a movable indicator carrying a cam, means for driving said indicator, and means to prevent vibration of said indicator and retrieve it to its zeroposition, said last-mentioned means comprising a pair of springs, and anti-friction means carried at the end of one of said springs and engageable with said cam, the second spring engageable with said anti-friction means, at the side of said cam opposite to that upon which the irst-mentioned spring is arranged, after an initial movement of the cam, to equalize the pressure on the anti-friction means.

2. In combination, a rotatable indicator carrying a cam, means for driving said indicator, and means for preventing vibration of said indicator and for retrieving it to its Zero position, lsaid last-mentioned means comprising a pair of leaf springs, antifriction means carried by one ofthe leaf springs, said antiefriction means being slidably engageable by said cam and engageable by the other spring, and means for adjusting the leaf springs.

8. In combination, a rotatable indicator carrying a cam, means for driving said indicator, and means for preventing vibration of said indicator and for retrieving it to its zero position, said last-mentioned means comprising a pair of leaf springs, and antifriction means carried by one of said springs and engageable by the other, the anti-fric` tion means being slidably engageable with the cam.

In testimony whereof, I have hereunto signed my name.

ARTHUR H. JOSEPH.

desire to secure 

